The middle ear is an air-filled space which contains three auditory ossicles providing mechanical linkage between the tympanic membrane or ear drum and the opening to the inner ear, commonly referred to as the "oval window." The three auditory ossicles are the malleus, the incus and the stapes. The malleus includes a handle portion and a head portion, the handle portion contacting the tympanic membrane. The stapes includes an arch, formed by a pair of limbs, and a footplate. The footplate communicates with the oval window leading to the inner ear. The incus couples vibrations from the head portion of the malleus, when the malleus handle vibrates in response to sound impinging on the tympanic membrane, to the arch of the stapes. The stapes footplate in turn communicates these auditory vibrations to the inner ear. The leaver action of the ossicles within the middle ear causes amplification of the sound vibrations with the result that greater vibrational force is experienced at the oval window than at the tympanic membrane.
Ossicular prostheses are implantable medical devices used to replace these middle ear structures when they become damaged. Presently, two conventional types of ossicular prostheses are available to hospitals for middle ear ossicular reconstruction. Total prostheses are designed to replace the malleus, incus and superstructure of the stapes while partial prostheses are designed to replace the malleus and the incus only. Presently, hospitals must stock both the total and partial prosthesis versions such that they can provide for all contingencies. In addition to having to stock two different types of prostheses, hospitals are typically required to stock multiples of each prosthesis in the event that one of a particular type is accidentally dropped or broken. In sum, hospitals carry a substantial burden in having to maintain stocks of both total and ossicular prostheses.
Thus, the need has arisen for an ossicular prosthesis which allows hospitals to significantly reduce their stocking burdens. Importantly, such a prosthesis should allow for flexibility without sacrificing the functionality provided by both the presently available total and partial prostheses.